Since 1988, the world has come very close to eradicating polio through the Global Polio Eradication Initiative, in which communication interventions have played a consistently central role. Mass media and information dissemination approaches used in immunization efforts worldwide have contributed to this success. However, reaching the hardest-to-reach, the poorest, the most marginalized and those without access to health services has been challenging. In the last push to eradicate polio, Polio Eradication Initiative communication strategies have become increasingly research-driven and innovative, particularly through the introduction of sustained interpersonal communication and social mobilization approaches to reach unreached populations. This review examines polio communication efforts in India and Pakistan between the years 2000 and 2007. It shows how epidemiological, social and behavioural data guide communication strategies that have contributed to increased levels of polio immunity, particularly among underserved and hard-to-reach populations. It illustrates how evidence-based and planned communication strategies - such as sustained media campaigns, intensive community and social mobilization, interpersonal communication and political and national advocacy combined - have contributed to reducing polio incidence in these countries. Findings show that communication strategies have contributed on several levels by: mobilizing social networks and leaders; creating political will; increasing knowledge; ensuring individual and community-level demand; overcoming gender barriers and resistance to vaccination; and reaching out to the poorest and marginalized populations. The review concludes with observations about the added value of communication strategies in polio eradication efforts and implications for global and local public health communication interventions.